﻿//-----------------------------------------------------------------------
// <copyright file="RenderUtility.cs" company="Nathan Miller">
// Copyright (c) Nathan Miller.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// </copyright>
//-----------------------------------------------------------------------
namespace TileTool.Render
{
    using System;
    using TileTool.Common.Math;

    /// <summary>
    /// Static class which contains utility methods for working with the rendering 
    /// classes.
    /// </summary>
    public static class RenderUtility
    {
        /// <summary>
        /// Given a point in canvas space (relative to the lower left of the canvas),
        /// transform it into world space.
        /// </summary>
        /// <param name="camera">Camera we are viewing with.</param>
        /// <param name="pos">Canvas point to convert.</param>
        /// <returns>Returns the canvas point in world space.</returns>
        public static Vector2D CanvasPointToWorld(ICamera camera, Vector2D pos)
        {
            if (camera == null)
            {
                throw new ArgumentNullException("camera", "Camera must be non-null.");
            }

            Matrix2D matrix = camera.Matrix;
            float x = pos.x - (camera.Canvas.Width * 0.5f) + matrix.Pos.x;
            float y = pos.y - (camera.Canvas.Height * 0.5f) + matrix.Pos.y;

            return new Vector2D(x, y);
        }
    }
}
